Export tables merged with BGP prefix hash

Until now, if export table was enabled, Nest was storing exactly the
route before rt_notify() was called on it. This was quite sloppy and
spooky and it also wasn't reflecting the changes BGP does before
sending. And as BGP is storing the routes to be sent anyway, we are
simply keeping the already-sent routes in there to better rule out
unneeded reexports.

Some of the route attributes (IGP metric, preference) make no sense in
BGP, therefore these will be probably replaced by something sensible.
Also the nexthop shown in the short output is the BGP nexthop.

1 files changed, 13 insertions, 6 deletions

diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h
index cca7873a..003893e0 100644
--- a/proto/bgp/bgp.h
+++ b/proto/bgp/bgp.h
@@ -156,7 +156,7 @@ struct bgp_channel_config {
   u8 aigp_originate;			/* AIGP is originated automatically */
   u32 cost;				/* IGP cost for direct next hops */
   u8 import_table;			/* Use c.in_table as Adj-RIB-In */
-  u8 export_table;			/* Use c.out_table as Adj-RIB-Out */
+  u8 export_table;			/* Keep Adj-RIB-Out and export it */
 
   struct rtable_config *igp_table_ip4;	/* Table for recursive IPv4 next hop lookups */
   struct rtable_config *igp_table_ip6;	/* Table for recursive IPv6 next hop lookups */
@@ -357,6 +357,8 @@ struct bgp_channel {
   HASH(struct bgp_prefix) prefix_hash;	/* Prefixes to be sent */
   slab *prefix_slab;			/* Slab holding prefix nodes */
 
+  struct rt_exporter prefix_exporter;	/* Table-like exporter for prefix_hash */
+
   ip_addr next_hop_addr;		/* Local address for NEXT_HOP attribute */
   ip_addr link_addr;			/* Link-local version of next_hop_addr */
 
@@ -378,8 +380,11 @@ struct bgp_channel {
 };
 
 struct bgp_prefix {
-  node buck_node;			/* Node in per-bucket list */
+  node buck_node_xx;			/* Node in per-bucket list */
   struct bgp_prefix *next;		/* Node in prefix hash table */
+  struct bgp_bucket *last;		/* Last bucket sent with this prefix */
+  struct bgp_bucket *cur;		/* Current bucket (cur == last) if no update is required */
+  btime lastmod;			/* Last modification of this prefix */
   u32 hash;
   u32 path_id;
   net_addr net[0];
@@ -388,8 +393,9 @@ struct bgp_prefix {
 struct bgp_bucket {
   node send_node;			/* Node in send queue */
   struct bgp_bucket *next;		/* Node in bucket hash table */
-  list prefixes;			/* Prefixes in this bucket (struct bgp_prefix) */
+  list prefixes;			/* Prefixes to send in this bucket (struct bgp_prefix) */
   u32 hash;				/* Hash over extended attributes */
+  u32 px_uc;				/* How many prefixes are linking this bucket */
   ea_list eattrs[0];			/* Per-bucket extended attributes */
 };
 
@@ -556,15 +562,16 @@ int bgp_encode_attrs(struct bgp_write_state *s, ea_list *attrs, byte *buf, byte
 ea_list * bgp_decode_attrs(struct bgp_parse_state *s, byte *data, uint len);
 void bgp_finish_attrs(struct bgp_parse_state *s, ea_list **to);
 
+void bgp_setup_out_table(struct bgp_channel *c);
+
 void bgp_init_bucket_table(struct bgp_channel *c);
 void bgp_free_bucket_table(struct bgp_channel *c);
-void bgp_free_bucket(struct bgp_channel *c, struct bgp_bucket *b);
-void bgp_defer_bucket(struct bgp_channel *c, struct bgp_bucket *b);
 void bgp_withdraw_bucket(struct bgp_channel *c, struct bgp_bucket *b);
+int bgp_done_bucket(struct bgp_channel *c, struct bgp_bucket *b);
 
 void bgp_init_prefix_table(struct bgp_channel *c);
 void bgp_free_prefix_table(struct bgp_channel *c);
-void bgp_free_prefix(struct bgp_channel *c, struct bgp_prefix *bp);
+void bgp_done_prefix(struct bgp_channel *c, struct bgp_prefix *px, struct bgp_bucket *buck);
 
 int bgp_rte_better(struct rte *, struct rte *);
 int bgp_rte_mergable(rte *pri, rte *sec);